The purpose of this research is to determine how phonatory functioning is altered in various types of laryngeal pathology, whether the concept of an optimum frequency of phonation has validity in different types of pathology and whether changing a patient's phonatory frequency alters phonatory functioning for speech. The following groups are being studied: normal males and females, patients with vocal fold nodules and polyps, and patients with unilateral recurrent laryngeal nerve paralysis. Tasks assssing phonatory functioning include maximum phonation time, maximum speaking time and counting for one minute. These tasks are performed under five experimental conditions during which phonatory frequency and intensity are manipulated systemtically. Measures evaluating phonatory function assess the duration of phonation and speaking time on one exhalation, acoustic power per respiratory volume and the stability of vocal fold vibration. These studies will determine the validity of the concept of "optimum pitch" currently used in treatment of many voice disorders. Improved understanding of how functioning of the larynx is compromised in different types of pathology and whether functioning is improved at different phonatory frequencies is important for furthering understanding of the phonetory mechanism in different types of pathology and new directions for treatment.